title: Diagnostic problems in the subtyping of renal tumors encountered by five pathologists.
abstract: The diagnostic problems in the subtyping of renal tumors were evaluated by a panel of five pathologists studying a set of selected tumors. Five pathologists independently assessed a single hematoxylin-and-eosin (HE)-stained slide from 28 selected renal tumors. After this independent assessment, the pathologists reevaluated and discussed all discordant cases. Additional HE-stained sections and immunohistochemically (IHC) stained slides were available. The generalized kappa for interobserver agreement was calculated. After independent assessment of the HE-stained slides, the five pathologists unanimously reached an agreement in the decision between malignant and benign in 82% of the cases. Fifty percent of the cases were correctly subclassified. The overall generalized kappa value for the five pathologists was 0.320 (CI 95% 0.090-0.551), which is considered a moderate agreement. A 100% agreement was reached for all 28 cases after examination of more slides from different tumor areas and IHC-stained sections. An accurate histologic distinction between benign and malignant renal tumors is possible on one HE-stained section. Correct assignment of the subtype is difficult on one slide alone and relies on IHC-markers and additional slides. Tumors composed of an eosinophilic cell type and tumors with a papillary growth pattern were the major causes of an incorrect diagnosis on an HE-stained section alone.
authors.affiliation: Department of Urology, (G4-249), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. i.p.kummerlin@amc.uva.nl
authors.forename: Intan
authors.initials: I
authors.lastname: Kümmerlin
authors.forename: Fiebo
authors.initials: F
authors.lastname: ten Kate
authors.forename: Frank
authors.initials: F
authors.lastname: Smedts
authors.forename: Thomas
authors.initials: T
authors.lastname: Horn
authors.forename: Ferran
authors.initials: F
authors.lastname: Algaba
authors.forename: Isabel
authors.initials: I
authors.lastname: Trias
authors.forename: Jean
authors.initials: J
authors.lastname: de la Rosette
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Laguna
mesh_terms: D000368:Aged; D001706:Biopsy; D002292:Carcinoma, Renal Cell / Q000145:classification / Q000473:pathology*; D004396:Coloring Agents; D003951:Diagnostic Errors / Q000517:prevention & control*; D004801:Eosine Yellowish-(YS); D005260:Female; D006416:Hematoxylin; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000145:classification / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D013194:Staining and Labeling / Q000379:methods
chemical_list: D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin